1. Field of the Invention
The present invention relates to a digital display device for digitally displaying the correct exposure time of a photographic camera.
2. Description of the Prior Art
Ammeters have been extensively employed as display devices for displaying the correct exposure time of photographic cameras. However, ammeters generally have the disadvantage that they are very prone to be damaged by mechanical shocks or vibrations and consequently have a low dependability factor particularly in the case where they are installed in portable instruments such as a camera. For this reason, light emitting diodes (hereinafter referred to as "LED's") or lamps have been recently accepted as a display device for camera exposure meters. However, prior art digital display devices utilizing such LED's or lamps still have the disadvantage that they require an extremely complicated circuit construction for converting analogue data representative of the brightness of an object to be photographed into the corresponding digital data. In addition, these digital display devices require a memory device for temporarily storing the immediately preceding digital data already displayed on the display during the period of time until a new digital data to be displayed on the display is obtained by the A-D converter.